Kidney Diet Tips

What is a normal phosphorus level?

The definition of normal phosphorus depends on if you have chronic kidney disease (CKD) in early stages or if you are on dialysis. Normal phosphorus on a routine blood test for the general public and CKD non-dialysis is 2.7 to 4.6 mg/dL. For dialysis patients the target range is 3.5 to 5.5 mg/dL.

Higher levels are associated with a 20% to 40% increased risk of death in dialysis patients. Lower levels below 3.5 mg/dL are associated with malnutrition.

Its obvious phosphorus is a big concern for kidney patients on dialysis. High levels are linked to elevated parathyroid hormone (PTH), loss of calcium from bones, and calcifications in soft tissues like heart, lungs, skin and eyes.

More recent news suggests phosphorus control in CKD patients who do not need dialysis may be more important than previously thought. In one study CKD non-dialysis patients with high-normal phosphorus levels were more likely to have coronary artery calcifications than those in the lower normal range.

Another recent study has shown that healthy people without kidney disease with high-normal phosphorus levels have a greater risk of coronary calcifications than those with low-normal ranges. In the future we can expect to hear more about phosphorus and health. A closer look at dietary phosphorus intake and other factors that contribute to phosphorus levels will reveal if this is our next big food-related health concern. In the meantime be sure to ask “What’s my phosphorus level?” at your next doctor visit. If levels are high, explore treatment with a low phosphorus diet, and if prescribed, a phosphorus-binding medication.

To learn more about phosphorus and how to control it, check out these articles:
Phosphorus and chronic kidney disease
Hidden phosphorus in your diet and how to control it

or watch these video clips:
How phosphorus binder work
Reading labels to find phosphorus

Sara Colman, RD, CDE

Sara is a renal dietitian with over 20 years experience working with people with diabetes and kidney disease. She is co-author of the popular kidney cookbook "Cooking for David: A Culinary Dialysis Cookbook". Sara is currently the Manager of Kidney Care Nutrition for DaVita. She analyzes recipes and creates content, resources and tools for the kidney community. In her spare time Sara loves to spend time with her young grandson, including fun times together in her kitchen.